Field of the Invention
The present invention relates to a motor having an internal coolant supply passage.
Related Art
Conventionally, techniques for cooling motors have been widely known. For example, a motor cooling device has been proposed that includes a temperature detection means for detecting the inside temperature of a motor, a coolant flow path provided to the motor, and a coolant supply means for supplying coolant to the coolant flow path, in which coolant is supplied to the coolant flow path from the coolant supply means in the case of the inside temperature of the motor detected by the temperature detection means becoming at least a predetermined value (Refer to Japanese Unexamined Patent Application, Publication No. 2006-121780).
However, with the conventional cooling method of a motor, it is difficult to cool the motor efficiently. For example, even when cooling the motor based on the inside temperature of the motor, it is not possible to sufficiently cool the winding of the stator or the rotor using the technology of Japanese Unexamined Patent Application, Publication No. 2006-121780. In particular, adverse effects such as a decline in bearing lifespan (grease lifespan) have been considered by the heat generation of the rotor transferring to the bearings of the motor, and the temperature of the bearings thus rising. For this reason, a motor having a coolant flow path (coolant supply path) therein has been demanded that is capable of efficiently cooling the motor.